If you are looking to increase your chances of getting your wife pregnant, then I have some useful information for you.  Male fertility is just as important as a females fertility because both are needed for things to work.  You have to look at your eating habits as well as your daily activities to figure out if there is anything that may be affecting you sexually.  So if you and your wife are having difficulties, just look into all the aspects of both your lives to see if something is unintentionally playing a negative role in one or both of your fertility.